1. Field of the Invention
The present invention relates to a belt tension adjusting device, and more particularly to a device for adjusting the tension state of a transmission belt for scanners so as to effectively adjust the transmission state of the belt, reduce costs, and increase competitiveness.
2. Description of the Prior Art
FIGS. 1A and 1B show two common ways of adjusting the tension of transmission belts of scanners. In FIG. 1A, a slide block pulley type is shown. It comprises a slide block 52, a spring 51, a belt 53, a carrier 54, and pulleys 55. FIG. 1B shows a rocker arm adjusting type, which includes an adjusting wheel 63, a spring 51, a belt 53, pulleys 55, a rocker arm 62, a carrier 54, a scanner frame 71, a glass surface 72, and a document 73. In both types as shown in FIGS. 1A and 1B, either slide blocks or rocker arms are required. This may cause damage to the belt, and the belt may become loosened, causing the transmission state of the transmission belt to slide during adjustment. Besides, the moving parts may wear, resulting in deflection of the tension of the transmission belt and defective transmission. In addition, there are numerous parts and components, which means increase in costs and reduction in competitiveness. All of these are problems that need to be solved.